Consistent export of shells by having each vertex defined only once and shared by edges
Based on IFC2x3
Initiator ISG Meeting-Prague
Effects Extended Coordination View
Date 2008 02 26
For each IfcClosedShell and IfcOpenShell, used e.g. in IfcFacetedBrep, or in IfcShellBasedSurfaceModel, each vertex shall only be exported once. Edges shall share identical vertices.